1. FIELD OF THE INVENTION
The present invention relates to a yarn winding apparatus of automatic bobbin changing type. More specifically, the present invention relates to an improvement of a yarn winding apparatus comprising a turret turnably mounted on a machine frame, a plurality of bobbin holders which are rotatably supported on the turret and which receive bobbins, and a separator which can be inserted into a space between the bobbin holders, whereby bobbins, onto which a yarn is wound, are automatically changed.
2. DESCRIPTION OF THE PRIOR ART
In a modern synthetic yarn manufacturing work, used is a yarn winding apparatus which comprises a turret turnably mounted on a machine frame and a plurality of bobbin holders which are rotatably supported on the turret and which receive bobbins.
When a predetermined amount of yarn is wound onto a bobbin to form a full bobbin, the turret is turned to replace the full bobbin with an empty bobbin and to continue the winding of the yarn onto the empty bobbin. The full bobbin is doffed from a bobbin holder, and then another empty bobbin is donned onto the bobbin holder.
In this case, there often may occur failure that a yarn end extending from the full bobbin entangles around the empty bobbin, after the turret has been turned. The occurrence of the above-described failure increases as the winding speed increases because a large amount of air flow accompanies the high speed rotation of the empty bobbin.
In order to obviate this failure, Japanese Utility Model Application Laid-open No. Sho 51-17550 discloses a method wherein compressed air is blown from outside toward the empty bobbin after the turret has been turned. However, such blowing of compressed air is insufficient to completely prevent the entanglement of the yarn around the empty bobbin, because the flow of the air accompanying the rotation of the empty bobbin increases as the winding speed increases. Furthermore, if this method is applied to a winding apparatus wherein a plurality of bobbins are inserted onto a spindle, the amount of consumed air becomes very large because air nozzles must be disposed for the respective bobbins, and accordingly, it is very difficult to practically use this method.
Japanese Patent Application Laid-open No. Sho 54-64148 discloses a method wherein a separator is inserted into a space between a full bobbin and an empty bobbin after a turret has been turned. However, the front end of the conventional separator disclosed in this Laid-open No. Sho 54-64148 merely reaches an imaginary line connecting the centers of the full bobbin and the empty bobbin. Accordingly, it is very difficult to obviate the influence of the air accompanying the rotation of the empty bobbin upon the full bobbin. Especially, when a yarn having a fine denier is wound, the yarn which is thin and light is easily involved in the influence of the accompanying air. Therefore, this method is insufficient to fully prevent the yarn end extending from the full bobbin from being entangled with the empty bobbin.
Japanese Patent Application Laid-open No. Sho 56-103558 discloses a method wherein the above-described two methods are simultaneously applied, however, this method still has both the defects caused by the above-described methods.
Furthermore, many mechanisms are proposed by which a separator is inserted into a space between bobbin holders. In these conventional mechanisms, a swing lever, one end of which is swingably supported, or a crank mechanism are usually used, and the separator is moved from outside to the space between the bobbin holders by swinging the swing lever or crank mechanism. Because of the mechanism, the distance, for which the separator is inserted into the space, is limited. Furthermore, the separator is slightly varied in a direction perpendicular to the advancing direction of the separator, i.e., along an imaginary line connecting the centers of the bobbin holders, because of the swinging mechanism. Because of these reasons, the separator cannot be fully inserted into the space between the bobbin holders.